Generally, a plurality of images of a scene having one or more exposure values are combined to generate a high dynamic range (HDR) image of the scene. Further, HDR image data is encoded from the HDR image and then displayed on display devices. However, most of the display devices cannot display the HDR image data as the HDR image data has a very wide dynamic range compared to a dynamic range of the display devices. Thus, in order to display the HDR image data, the dynamic range of the HDR image data needs to be mapped with the dynamic range of the display devices. Tone mapping is a technique used to map the dynamic range of the HDR image data with the dynamic range of the display devices. Existing techniques for performing tone mapping on the HDR image generate a tone mapping curve by assuming a certain bit-depth or granularity for irradiance information of the scene. These techniques then map the dynamic range of the HDR image data with the dynamic range of the display devices using the generated tone mapping curve. However, the assumption taken by these techniques, to generate the tone mapping curve, may lead to posterization or result in inefficient use of available display levels for satisfactory representation of the dynamic range of the HDR image data. Further, the ill effects of this assumption are severe when the images used for generating the HDR image are less in number. Using a high number of images for HDR image generation may lead to higher capture time and may further require a higher processing power. Therefore, making it unsuitable for a device like a camera phone. In addition to getting image details in all the irradiance ranges of the scene, the tone mapped HDR image is often expected to appear dramatic and hence have richer details and vivid colors than any of the plurality of images. Generally, this is achieved by enhancing edges and boosting colors which can cause distortions in the image and hence undesirable.
The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.